Spurred by an increasing demand for higher density information storage, there has been an expanded effort to develop improved, high-density magnetic recording media. As a result, considerable attention has been focused on metallic, thin-film magnetic recording media which are capable of higher recording densities than pigment/binder media. Metallic thin film media may be used in perpendicular recording when they have an easy axis of magnetization perpendicular to the surface of the recording layer (see U.S. Pat. No. 4,210,946).
A problem common with known metallic, thin-film magnetic recording media resides in their susceptibility to wear and abrasion. Transducer heads contacting the metallic thin film will have a tendency to erode or otherwise damage it. Even slight erosion will result in considerable loss of data when high bit density recording is employed. Applications involving erosion and severe wear of metallic thin film media are on the increase, with video tape and electronic cameras being two examples.
The thin film media of U.S. Pat. No. 4,210,946 is a cobalt/chrome alloy. However, the surface of cobalt/chrome can be hard and abrasive and can scratch the surface of a recording/playback head causing the failure of both the medium and the head.
Organic protective topcoats or lubricants for thin film ferromagnetic media have been investigated for achieving satisfactory protection of the media. Such coatings include waxes of the fatty acid ester type (e.g. carnauba wax.) Other lubricants known in the magnetic recording media art are silicones, liquid paraffins, straight chain fatty acids such as myristic acid, palmitic acid and stearic acid. The disadvantages of some such protective topcoats include a build-up of a lubricant material on the transducer during the record/playback process, leading to a deterioration in performance and possibly clogging of the recording or playback transducer.
It is the object of this invention to improve the durability of thin metal film magnetic media through a surface modification of such media.